Verrry interesting article. Thanks for your keen insights into the newer generation of stoves, and it's fascinating to see a technical examination of the Hornet (FMS-300t). Very interesting that they've come up with something so diminutive. They really are advancing by leaps and bounds.

Let us hope that winter stoves follow suit and make the advances of summer stoves. I got a Kovea Sider in June or so of last year, and it is such an improvement in compactness over the stoves that came before. So far, I'm not quite as impressed with the FMS-117t/FMS-118 stoves. They seem bulky by comparison and there have been some reports that you have to fiddle with them to get the fuel to vaporize properly, but if the Fire Maple engineers are capable of designing the FMS-300t, then surely improvements will follow.

To really get a good fuel though, one of the Western heavy weights I think needs to enter the fray. Coleman tried and failed with PowerMax which is likely to scare off the likes of Primus, Optimus (Katadyn), and MSR. Coleman of course didn't have the perception in the public eye of being a cutting edge backpacking stove company. They're more seen as the car camping/family camping company and certainly not cutting edge. Let us hope that a Western company hoping to keep it's slipping edge will try something different in the area of fuel.

It's too bad the smaller propane canisters never caught on here. I think everyone is happy with the standard long, thin 400g canisters of 100% propane. The lighter ones were more expensive, and I think no one saw the need.

"Can a winter stove go any lighter than the FMS-118? Oh yes, for sure. (Watch this space.) But will it be sold by a traditional Western stove company? Ah … that's a good question."

Your killing us with anticipation.

Given that I use Esbit or alcohol in 3 season conditions, I am only interested in a canister stove for winter. And therefore it needs to be an invertable/remote canister stove. I'm guessing there are a lot of us pining after something that would look like a FMS-118T. Is this what you are referring to? How long do we have to wait for the secret unveiling you seem to be alluding to?

I'm still very impressed with the innovation behind the FMS-300t. I'm not sure if I like the idea of a roarer burner (or something close to it) on a canister stove, but the compactness! Nice! The one thing I fault the Heat Core (FMS-116t) on is (to my mind) it's lack of compactness.

QUESTION: How's pot stability? In particular, how's pot stability compared to a Heat Core (FMS-116t)? And if I may ask, what pot were you using with the stove?

Excellent article. I'm curious about wind screens. Canister stoves have unusual demands from a wind screen perspective. BPL has written about this before (it may have been you, Roger, but I've forgotten). With a canister stove, you want to shield the burner from excess wind, allow enough air in (like any wind screen) but not let the canister get too hot. An upright stove sits up pretty high, which adds to the demands of a wind screen. You can make your own (and I imagine most people do) but if folks are thrilled about a better stove because it is a few grams less than an old one, than it makes sense for someone to sell a windscreen specifically designed and optimized for that stove. One of the reasons that the Caldera Cones are so popular is that the wind screen is integrated, and sold with the product.

A couple things popped out at me.
You wrote:
"…The vortex burner is epitomised by the MSR XGK stove, which makes a very loud noise. In the vortex design the fuel comes out of a jet into a semi-enclosed volume and hits a baffle plate: the round dish in the middle supported by glowing wires. While doing this it drags air into the fuel stream from the inlets around the bottom so it can burn, but the flow is unstable. The unstable flow and the design of the burner create a vortex of air that oscillates like mad, and the very loud roar of the stove is due to this chaotic vortex oscillation."
and
"…Okay, there is no obvious sidewall and no obvious splash plate as are found in a typical vortex burner such as is shown in the forth photo for instance. But wait a moment – the base of the pot can function as a splash plate, and the air rushing inwards can act as a soft sidewall. You can't see the flames making a full ring as the combustion has almost completed when only halfway around the loop. But there is an inrush of air at the level of the burner head. So what happens when you take the pot off, as in the previous photo? The shape of the flame changes a bit – it sticks up a lot more, and so does the sound. Yep, the pot is shaping the flame like a splash plate."

I would submit that the "roar" is not necessary. Carefull tuning of the plate on the roarer style burners will significanly reduce the sound. Indeed, after running for a minute or so, I turn my stove down to the point of just hissing…no roar at all. This is simply a byproduct of the "bell" design. It is, in effect, overloading the mixing chanber then repeating…

The holes on the 300t are simply to facilitate lighting. No mixing means a no combustion. Or, sooty orange flames. Try it by taping off the vents, easy to see.

Ahh, as far as reducing weight, removing the flame spreader certanly helps. Along with all the fancy brass nuts, et all. A screw on stem would double as a lock for the jet. But, as you say, the benefits of an extra few grams is hardly worth it.

Minor points on an otherwise good article.

Other low pressure gas mixes should be examined before trying to come up with a standard. For example, acetylene can be disolved in isobutane at relativly low pressures, too, and has significantly higher heat.

A couple of years back I read your MYOG article about modifying a stove so that it would work in the depths of winter as an inverted canister stove. I was intrigued, so I set out to find the Brunton stove stand, bought one and then got busy with other projects. This article inspired me to tackle that original project (thanks)! I've now paired the Brunton stand with my Snow Peak Lite Max Ti- 7.2 oz total – and used a stout piece of copper wire to preheat the brass fuel tube at the base. It works like a charm! I'm going out this weekend for a bit of winter camping and can't wait.

> How's pot stability?
Good question. So far I have had zero problems with that. I have used a Trangia kettle and MSR Titan pots (big and small).

Mind you, a vigorous stir of a pot on any stove without some care can send it flying anytime. Both the FMS-300 and the FMS116T have robust pot supports, and I don't really see a lot of difference between the two.

> I would submit that the "roar" is not necessary. Carefull tuning of the plate on the
> roarer style burners will significanly reduce the sound.
Hum … I have not experiments with that idea, so I can't say. A bit hard to see how tuning would get rid of the chaotic oscillation entirely though.
What's the matter with that nice healthy roar anyhow? It says 'cooking'!

> For example, acetylene can be disolved in isobutane at relativly low pressures,
> too, and has significantly higher heat.
Now that thought is frightening! The BP for acetylene is -84 C. OK, it would make for a fantastic winter fuel, but the vapour pressure at +30 C is 50 bar. Compare that with propane, which is about 10 bar at +30 C. We can't get 100% propane in our canisters becasue of the pressure. For acetylene you would need an extremely robust canister or an extremely low % of acetylene.

your efficiency can go down to less than 50% if it's windy, if it doesn't get blown out completely

It would be interesting to know more about efficiency, because the fuel and canister weighs a lot more than the stove. It takes maybe 1/8 or 1/4 ounce of isobutane to boil a pint of water, I wonder how much it would theoretically take at 100% efficiency…

Excellent article. I'm curious about wind screens. Canister stoves have unusual demands from a wind screen perspective. BPL has written about this before (it may have been you, Roger, but I've forgotten). With a canister stove, you want to shield the burner from excess wind, allow enough air in (like any wind screen) but not let the canister get too hot. An upright stove sits up pretty high, which adds to the demands of a wind screen. You can make your own (and I imagine most people do) but if folks are thrilled about a better stove because it is a few grams less than an old one, than it makes sense for someone to sell a windscreen specifically designed and optimized for that stove. One of the reasons that the Caldera Cones are so popular is that the wind screen is integrated, and sold with the product.

The reason that they don't sell a windscreen with a canister stove is generally one of liability. A windscreen could cause your canister to overheat and explode. Most stove companies say "never" in their instructions. Of course people do it all the time in real life, but if something happens the stove company can say "you went against our advice" in court. It's reasonably safe if you're careful. Lot's of good windscreen ideas at Jerry's link.

The reason that they don't sell a windscreen with a canister stove is generally one of liability. A windscreen could cause your canister to overheat and explode…

Yes, but a windscreen like the third one in that thread is actually safer than no windscreen at all. It shields the canister from heat. That is similar to the one I saw on this site. I tried to make one, but failed. I would gladly pay for one, but I don't know anyone that sells one. So I use a basic windscreen, but I have to make sure it doesn't get too hot. In other words, I take more of a risk because I don't know anyone that sells a good windscreen. It is also a bit heavier than an optimized windscreen (since it is blocking wind from reaching areas that don't need blocking).

The one that sits on the radiation shield is very similar to the one I remember being described on this site. You are right, the bowl one is also very good. They both are quite similar, in that they form a barrier between the heat source and the canister. I would think they would make things safer.

You are right in general — I think they don't want to mess around with windscreens unless they are completely foolproof (like the Jetboil). The Jetboil is really nice, but comes with a weight penalty. Something significantly lighter but just a bit less efficient (and not home made) would be really nice.